In our two part series on position battles, I declared young running backs Eddie Lacy and Johnathan Franklin as "locks" to make this year's roster. I stand by that prediction, and here's why: between them, they represent a perfect example of the NFL's "multi-back" trend.

You can't read any article about Eddie Lacy without hearing a reference to him as a "big back" or a "pounder" or (my favorite) a "thumper" (he goes blasting through the line, and then you hear a "thump" and suddenly a linebacker is on his backside). Supposedly, that's perfect for what the Packers need: a little grit, a little attitude, and the ability to get tough yards out of the running back position.

As a bonus, Lacy is considered an above average receiver out of the backfield, giving the Packers the option of keeping him on the field on third downs as well.

However, Johnathan Franklin is also considered a good player in space, which could move him into the de facto "third down back" spot. Franklin is a little quicker and a little shiftier than Lacy, and that quickness could be what gets him on the field on third downs or really any down, for that matter.

Franklin and Lacy could also be used to fill in for each others' weaknesses. For all his power, there is some concern that Eddie Lacy might not be quite quick enough to be consistently productive in the NFL. Franklin, however, is quite speedy, and could be used to take some of the speed-related pressure off of Mr. Lacy.

Conversely, Franklin is a very little back. He's listed at 5'10", although he might actually be closer to 5'8", and he weighs only 205 pounds. Power, obviously, is not going to be his strong suit. But Lacy, on the other hand, weighs in at a robust 231 pounds (and judging by this Twitter picture and this Vine video, might be closer to 251) and is significantly taller at 5'11". Though he may not be speedy, he's certainly built to take an NFL-level pounding.

The point is, we should not be surprised to see the Packers' two newest running back assets used as complementing parts frequently. The Packers have paid lip service to guys like Alex Green and James Starks, but considering their skill sets, it's almost a given that Lacy and Franklin will have every opportunity to be the two main backs this year.

For a great example of Lacy's power running, check out his evisceration of Notre Dame during the National Championship game.

http://www.youtube.com/watch?v=d9NeqNEApgU

And for a look at Franklin's versatility and quickness, here's Johnathan Franklin doing it through the air and on the ground against Nebraska.

http://www.youtube.com/watch?v=Kqu06Tj9dTw